Gap junctions in goldfish preoptic ependyma: regional variation in cellular differentiation

William A. Gregory, Michael V.L. Bennett

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Ependyma adjacent to the goldfish preoptic neurosecretory nucleus was examined with transmission electron microscopy. Ependymal cells adjoining the rostroventral end of the nucleus were spindle-shaped with their long axes perpendicular to the ventricular surface. Gap junctions and desmosomes were common near the apical (ventricular) ends of these cells, and less frequent laterally in the ependymal layer. Ependymal cells in more caudodorsal preoptic regions (adjacent to large neurosecretory cells) were progressively more pleomorphic. The frequent occurrence of apparently internalized gap junctions and of gap junction fragments enclosed within lysosome-like organelles indicated extensive turnover of these junctions, or uncoupling. Ependymal cells in the caudodorsal region formed gap junctions on their lateral and basal (abluminal) surfaces with glial processes containing bundles of intermediate filaments. Subependymally, these processes (presumptive radial glia) were parallel to one another and coupled together by gap junctions. Neurites containing dense core vesicles occasionally invaginated into ependymal cells in the caudal region, but did not appear to form gap junctions. Previous observations indicate continuing maturation and growth of the goldfish preoptic area with neurosecretory cell formation rostroventrally and a rostroventral to caudodorsal gradient of maturation. The present findings suggest a parallel and related gradient in preoptic ependyma. Ependymal cell differentiation possibly involves loss of gap junctions, and radial migration or differentiation into underlying neurons and glia.

Original languageEnglish (US)
Pages (from-to)205-216
Number of pages12
JournalDevelopmental Brain Research
Issue number2
StatePublished - Aug 1 1988


  • Annular gap junction
  • Astrocyte
  • Ependyma
  • Glia
  • Goldfish
  • Neurosecretion
  • Preoptic Area
  • Radial glia

ASJC Scopus subject areas

  • Developmental Neuroscience
  • Developmental Biology


Dive into the research topics of 'Gap junctions in goldfish preoptic ependyma: regional variation in cellular differentiation'. Together they form a unique fingerprint.

Cite this